The invention relates to a probe head for a coordinate measuring machine and more particularly to a probe head having a replaceable, miniaturized probe system with a rigid stylus that forms a structural unit together with a membrane-type sensor system that deforms in a predetermined way when a force acts on the stylus.
In the case of conventional coordinate measuring machines, it is often necessary to replace the stylus so that measurement tasks of different types can be carried out consecutively. These measurement tasks include, for example, the measurement of bores of different depth, the measurement of bores of different inside diameter and the like. It is desirable to have styluses of different lengths and having stylus balls of different diameter at the end.
In an embodiment, DE 101 08 774 A1 discloses a new type of a miniaturized probe system for a probe head, wherein the stylus is mounted on a membrane-type arrangement which is square in plan view and which has a thickened periphery edge. Located in the middle of the arrangement is another thickened portion, which supports the stylus. Located between the edge and the middle is a membrane-type zone which is provided with piezoresistive elements or with strain gauges on a side facing away from the stylus. Deflecting the stylus leads, in this case, to the membrane-type zone being distorted or deformed and therefore to a signal being produced via the piezoresistive elements or the strain gauges. According to DE 101 08 774 A1, such a probe system cannot be replaced. Rather, the thickened periphery edge of the probe system is permanently fixed to the probe head.